Direct side force control device

ABSTRACT

An airplane using the rudder and speed brakes located at the aileron position, or otherwise located at the wing tips and capable of differential operation, to provide a pure side force acting to alter the horizontal flight path of the plane, without sideslip or the need for roll movements normally associated with such maneuvers. This device is hereinafter referred to as the Side Force Control System.

ilriite Sites R Wheldon tet n91 DIRECT STDE FORCE CONTROL DEVICE [75]Inventor: Wilbert G. Wheldon, Palos Verdes Peninsula, Calif.

[73] Assignee: Northrop Corporation, Los Angeles,

Calif.

[22] Filed: Aug. 24, 1970 [21] Appl. No.: 66,449

[52] 11.8. C1 244/83 E, 244/42 DC, 244/77 E. [51] lint. Cl. B640 13/04[58] Field of Search... 244/83 R, 83 C, 75 R, 76 R, 244/77 R, 77 A, 77E, 87, 90 R, 90 A, 91, 42

R, 42 D, 110 R, 110 A, 42 DC, 113

[56] References Cited UNITED STATES PATENTS 2,480,040 8/1949 Mitchell244/87 2,868,481 1/1959 Seamans et a1. 244/77 R 2,612,329 9/1952Crandall et a1. 244/90 R X Jan. 22, 1974 1,907,374 5/1933 Van Atta244/87 2,707,602 5/1955 Kauffman.....

2,958,484 1 1/1960 Ross 3,373,958 3/1968 Sims 244/77 E PrimaryExaminerMilton Buchler Assistant Examiner-Barry L. Kelmachter Attorney,Agent, or Firm Willard M. Graham 5 7 ABSTRACT 8 Claims, 3 DrawingFigures pi L QT"5 QQNTRQLLER P C) S \TlON TRANSDUCER LEFT SPEED BRAKEPlLO'fS smr. FORCE Posmou WAusDucER coNrno: SYSTEM Mom; swi'rcn momSPEED BRAKE POSm N msbucew.

LEFT SPEED BRAK goNTRoL MIUAT R 5P BR. POSlllON COMPA ATOR e AMPLW RlGHTSPEED asthma comm ACTUATOR [E 'SPEED I BRAKE I smr; SLIP ANGLE SENS Rmam 5P E ED BRAKE:

(AW DAMPER e LELTRO N s com vmems AssY (Aw DAMPEP- co NT am.

RUDER PAIENIE JAMwQH LoT's CONTROLLER P O s \T\ON TRANSDUCER LEFT SPEEDBRAKE P0$|T|0N WANSDUCER RKSHT SPEED BWE PosmoN TRANSDUCER LEFT SPEED BF;

CONTRQL. kcrum' i R ER. Dosnlo (-OMPIXRATOR E RK-LHT SPEED ERMAE CONTRDL2/ AMPLFER ACTUATOR 5E) 22 '1 K PT SPEED BRAKE j SDE sup RGm SPEED HQ/ANGLE SENSOR BRAKE YAw DAMPER E LECJ'RO was COMPONENTS AssY YAw DAMPER.4| Co NTILOL.

RUDDER W2 ZWleZ/m 1 DIRECT SKDE FORCE CGNTRGL DEVICE The presentinvention relates to control surfaces for airplanes, and moreparticularly to military airplanes, including a rudder or like controlsurface cooperating with speed brakes enabling the airplane to make aflat turn thus changing its flight path without the accompa- -nying rollnormally associated with a conventional heading which degrades thepilots ability to track accurately is according to the presentinvention, of heading, which problem is eliminated by the inventiondescribed herein.

According to the present invention, the airplane is equipped with aconventional rudder or like control surface, and split-type speed brakesat each wing tip which, in addition to their normal operation, areadapted to function differentially with respect to each other to producea yaw moment which in turn is balanced by suitably positioning oppositerudder enabling the airplane to effect changes in the flight paththereof while maintaining a wings-level attitude. Yawing momentsproduced by the speed brakes are automatically balanced by oppositerudder deflection leaving an unbalanced side force on the airplanecausing the desired radial accelerating force to produce a flat turn.This is especially useful in dive bombing runs as pointed out abovesince it eliminates the undesirable pendulumlike responses in theoptical sight thereby enabling the pilot to easily align the sight withthe target thus eliminating this extraneous source of error to the pilotwhile tracking.

Accordingly it is an object of the invention to provide an airplaneincorporating control surfaces and control means whereby wings-levelstability of the airplane is permitted to be maintained at such times asits flight path azimuth is altered as in a turn for example, essentiallywithout sideslip or roll.

In the accompanying drawings:

FIG. 1 is a plan view of an airplane incorporating the control surfacesand apparatus enabling the airplane to function in the manner disclosedherein. Also shown are forces acting on the airplane at such times asits flight course is being changed in accordance with this invention tomake small steering corrections while tracking a ground target.

FIG. 2 is a diagrammatic side elevational view showing the split-typespeed brake of FIG. I as indicated by the line 22.

FIG. 3 is a block diagram showing a preferred form of the componentscomprising the rudder and speed brake interconnecting system.

Referring to the drawings, a military type airplane Ill includingfuselage 12, right and left wings and tail empennage l4, l6 and 17,respectively, is shown in FIG. 1. The empennage 17 includes a verticalmember 18 having a fixed relation with respect to the airplane ll and aconventional rudder member 19. However, the members 18 and 19 may be ofunitary construction referred to as an all-movable vertical tail. Theairplane l 1 also includes split-type speed brakes 21 and 22 of theconventional structural type described and shown in U. S. Pat. No.2,612,329 granted Sept. 30, I952 for example. The airplane It alsoincludes an on-off mode switch 23 in a rudder-speed brake electronicinterconnect 2d, and a pilots system controller 36 (FIG. 3). Thecontroller 36 may be an independent manually operated component as shownor may be actuated by a normal control member (not shown) of theairplane 11 such as the rudder pedals. The switch 23, upon being movedto on, causes control movements of controller 36 to act through theinterconnect 24 and deflect the speed brakes 2K, 22 and the rudder 19 bythe novel means described below.

Referring to FIG. 3, the components comprising the rudder-speed-brakeinterconnect 24- are shown. Signals originated by movements of thepilots controller indicated by the numeral 36 are transmitted to aspeedbrake position comparator and amplifier 37, which signals are inturn transmitted to left and right speed brake control actuators 38 and39, respectively. Positions assumed by the left and right speed brakes21 and 22 are sensed by position transducers 34 and 35 and providesignals necessary to then correctly position the rudder 119 to balancethe speed brakes induced yawing moment. The rudder now is producing apure side force on the airplane which accelerating force causes theairplane to make a flat turn. In so doing a small amount of residualsideslip may be induced which is sensed by a sideslip angle sensor 43and corrects the signal transmitted to a yaw damper actuator indicatedby the numeral 41 which in turn corrects the rudder position to null thesideslip angle.

During dive bombing runs in which stores are to be dropped, theaccomplishment of directional changes without the need to intentionallyroll the airplane will eliminate the pendulous effect on the armamentsight (not shown). Thus tracking of a target will be rendered lessdifficult due to this improvement. Also target lead time neededutilizing the conventional rudder aileron bank and turn maneuver iseliminated. The flight control means disclosed herein functions in anovel manner to eliminate or minimize these objections.

Referring further to FIG. 1, it is assumed that the flight path of theairplane 11 is to be altered to the left during the course of a bombingrun. To effect this change the switch 23 is first moved to its on"position energizing the interconnect 24. The pilot will move hiscontroller 36 in the left turn direction as far as deemed necessary forthe desired rate of correction.

The left speed brake 21 first opens as shown in FIG. 2, the right one 22remaining closed, or if already in the dive with both brakes open thesame amount, the left brake 21 opens more and the right brake 22 closescorrespondingly so that net drag change is small. This gives theairplane a short-time initial left yaw which starts turning the noseheading to the left. Positions now assumed by the left and right speedbrakes 21 and 22 provide signals from transducers 34 and 35 to move thetrailing edge of rudder 119 to the right to balance thespeedbrake-induced yawing moment, i.e., yaw moment due to speed brakeinduced drag (F F )a equals yaw moment produced by the rudder (F )(b)leaving only the unbalanced side force due to rudder F The momentsrepresented by arrows 28 and 29, acting about the center of gravityindicated at 33, due to rudder deflection and differential speed-brakedrag, respecti ely, being equal and opposite, cancel each other, thelinear side force F can be transposed to the c.g. 33 of the airplane 11leaving only the pure side force indicated by arrow 32. The side force32 results in a change in the flight course. The sideslip sensor 43 inconjunction with yaw damper 41 causes rudder 19 to assume a positionthat will cancel any residual sideslip.

When the airplane ll assumes its desired new flight path the pilot easesoff on the side force controller 36 as required to maintain accuratetarget tracking, in a straight forward direction again.

I claim:

1. The method for executing a flat turn of an airplane equipped withconventional opposite wing-mounted split-type speed brakes andconventional rudder means, comprising applying yaw with said speedbrakes followed by opposite rudder deflection.

2. The method of executing a wings-level flat turn with an airplaneequipped with conventional opposite wing-mounted split-type speed brakesand conventional rudder means, which comprises producing a yaw in onedirection by means of differential speed-brake deflection and thencancelling the speed-brake yaw moment by deflecting the rudder in theopposite direction while the speed brakes remain differentiallydeflected, thus leaving an unbalanced lateral side force on the airplaneto accompany the initial speed-brake induced yaw.

3. in an airplane which includes a rudder and opposite-wing-mountedsplit-type speed brakes, control means operable to perform a flat turncomprising:

3. electronic means interconnecting the control means for said rudderwith the control means for said speed brakes, said speed'brake controlmeans being operable to actuate said speed brakes so that said speedbrakes open and close differentially for yaw-producing moments,

b. a manually controlled switch operable to actuate d. and side forcecontrol means in said interconnecting means responsive to said turncontroller when said interconnecting means is operable to differentiallyoperate said speed brakes in one yawproducing direction and to deflectsaid rudder in the opposite yaw-producing direction,

e. whereby the lateral side force on said airplane from said rudderdeflection combined with an initial yawing motion started by said speedbrakes differential operation can produce a wings-level flat turn ofsaid airplane.

4. Apparatus in accordance with claim 3 wherein said split-type speedbrakes comprise a pair of split-flap type brakes conforming to thetrailing edge of each of the left and right wing portions of saidairplane when said speed brakes are closed.

5. Apparatus in accordance with claim 3 wherein said differentialactuation of said speed brakes includes opening of the speed brakes ononly one side of said airplane if the other side speed brakes areinitially closed.

6. Apparatus in accordance with claim 3 wherein said side force controlmeans comprises a. a speed brake position comparator,

b. left and right speed brake control actuators having their inputsconnected respectively to said position comparator,

c. left and right speed brake position transducers having their outputsrespectively connected back to said position comparator, and

d. means connecting the output of said position comparator to thecontrol means for said rudder.

7. Apparatus in accordance with claim 6 wherein said rudder controlmeans includes a sideslip angle sensor and a yaw damper.

8. Apparatus in accordance with claim 6 wherein said speed brakeposition comparator includes amplifier means for regulating ruddermovement to an amount responsive to speed brake position to cancel theyaw moment produced by the initial differential movement of said speedbrakes, thus leaving an unbalanced lateral side force on said airplanedue to rudder deflection which produces a flight path direction changeaccompanying the initial yaw, whereby said wings-level flat turn isaccomplished.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No- 3178L003 lannary zz mz4 Wilbert G. Wheldon Inventor(s) It is certifiedthat error appears in the above-identified patent and that said LettersPatent are hereby corrected as shown I below:

Column 1 lines 18 23. The sentence here should read This pendulous sightmotion which degrades the pilot's ability to track accurately is causedby the banked Wings associated with conventional aileron control ofheading,

which problem is eliminated by the invention described herein.

Signed and sealed this 12th day of November 1974.

(SEAL) Attest:

McCOY M. GIBSON JR; C. MARSHALL DANN Attesting Officer Commissioner ofPatents USCOMM'DC 60376-PG9 U.S. GOVERNMENT PRINTING OFFICE: B69. 930

ORM PO-105O (10-69)

1. The method for executing a flat turn of an airplane equipped withconventional opposite wing-mounted split-type speed brakes andconventional rudder means, comprising applying yaw with said speedbrakes followed by opposite rudder deflection.
 2. The method ofexecuting a wings-level flat turn with an airplane equipped withconventional opposite wing-mounted split-type speed brakes andconventional rudder means, which comprises producing a yaw in onedirection by means of differential speed-brake deflection and thencancelling the speed-brake yaw moment by deflecting the rudder in theopposite direction while the speed brakes remain differentiallydeflected, thus leaving an unbalanced lateral side force on the airplaneto accompany the initial speed-brake induced yaw.
 3. In an airplanewhich includes a rudder and opposite-wing-mounted split-type speedbrakes, control means operable to perform a flat turn comprising: a.electronic means interconnecting the control means for said rudder withthe control means for said speed brakes, said speed brake control meansbeing operable to actuate said speed brakes so that said speed brakesopen and close differentially for yaw-producing moments, b. a manuallycontrolled switch operable to actuate said electronic interconnectingmeans from an inoperable to an operable condition, c. a pilot''s turncontroller connected to said electronic interconnecting means, d. andside force control means in said interconnecting means responsive tosaid turn controller when said interconnecting means is operable todifferentially operate said speed brakes in one yaw-producing directionand to deflect said rudder in the opposite yaw-producing direction, e.whereby the lateral side force on said airplane from said rudderdeflection combined with an initial yawing motion started by said speedbrakes differential operation can produce a wings-level flat turn ofsaid airplane.
 4. Apparatus in accordance with claim 3 wherein saidsplit-type speed brakes comprise a pair of split-flap type brakesconforming to the trailing edge of each of the left and right wingportions of said airplane when said speed brakes are closed. 5.Apparatus in accordance with claim 3 wherein said differential actuationof said speed brakes includes opening of the speed brakes on only oneside of said airplane if the other side speed brakes are initiallyclosed.
 6. Apparatus in accordance with claim 3 wherein said side forcecontrol means comprises a. a speed brake position comparator, b. leftand right speed brake control actuators having their inputs connectedrespectively to said position comparator, c. left and right speed brakeposition transducers having their outputs respectively connected back tosaid position comparator, and d. means connecting the output of saidposition comparator to the control means for said rudder.
 7. Apparatusin accordance with claim 6 wherein said rudder control means includes asideslip angle sensor and a yaw damper.
 8. Apparatus in accordance withclaim 6 wherein said speed brake position comparator includes amplifiermeans for rEgulating rudder movement to an amount responsive to speedbrake position to cancel the yaw moment produced by the initialdifferential movement of said speed brakes, thus leaving an unbalancedlateral side force on said airplane due to rudder deflection whichproduces a flight path direction change accompanying the initial yaw,whereby said wings-level flat turn is accomplished.